Back before the Christmas break, it looked like Ofcom was ready to do its duty and stop the BBC from adding digital rights management technology to its high-definition broadcasts. After all, DRM doesn't actually prevent copying – even the BBC agrees that the scheme it's proposed won't stop a determined copier, and once that copy is on the internet, everyone else will be able to get at it with a couple of clicks.

And DRM imposes social, monetary and public interest costs: a DRM scheme will never be able to embody the flexibility built into the law that instructs judges to carefully weigh up the copyright holder's exclusive rights against the public's legitimate use of copyrighted works for personal archiving, format-shifting, commentary, education, and the other traditional uses that have fallen outside of the exclusive purview of copyright corporations to approve.

And because DRM requires that devices hide things from their owners – that they prevent owners from gaining access to their media except according to the DRM's rules – that means that DRM can't be implemented in free/open source software. The BBC's plans will mean locking open devices – the kind of thing that British entrepreneurs can knock up in a garage without permission or licences from giant multinationals – out of the market.

Finally, since the rules for the BBC's DRM are set by a consortium that takes its orders from the Hollywood studios, this plan would move the BBC's regulation from Ofcom to studio bosses 9,000 miles away in California. You see, the BBC's plan is to scramble some key information needed to watch high-def broadcasts, a block of data that includes subtitles and other information used by disabled people, who are making increasing use of open devices that can be readily repurposed to add assistive features.

Ofcom may decide to order the BBC to allow these open devices to unscramble broadcasts, but the BBC doesn't have the authority to grant this exception – it will have to be decided by the studio heads (from the same companies whose trade association, the MPAA, has come out against a UN World Intellectual Property Organisation treaty to safeguard the rights of blind and disabled people to gain access to copyrighted works).

So when Ofcom told Auntie that it hadn't made the case for DRM, that the social harms outweighed the benefits, and that it wouldn't allow the BBC to add DRM after all, it seemed like the regulator had really stepped up to do its duty: protecting the public interest, protecting the rights of disabled people, protecting the rights of British firms to field innovative new devices into the British marketplace.

And then Ofcom caved. In its latest consultation on the matter, Ofcom takes it as a given that the BBC will be allowed to add DRM to our licence-funded television signals. Instead of asking whether there is a case for DRM, Ofcom offers up a string of "have you stopped beating your wife yet?" questions, like, "Do you agree that the BBC's proposed approach for implementing content management would safeguard citizens' and consumers' legitimate use of HD content, and if not, what additional guarantees would be appropriate?"

Did you catch that? Not "Can DRM be used to safeguard legitimate uses?" but rather, "Which DRM should we use to make sure this happens?"

What caused Ofcom to give up its commitment to sanity in TV policy? The clue is here, in the opening: "The BBC believes copy management would broaden the range of HD content available on DTT, and hence would deliver benefits to citizens and consumers."

In other words: the BBC has been told by its licensors that they won't allow their programmes to be aired in high-def without DRM. When I met with Ofcom about this, it was clear that this was uppermost on their minds, the threat that "high quality content" would migrate away from public service media and into the private broadcasters' silos, where Ofcom wields far less power and influence.

But how credulous do you have to be to take a threat like this seriously? Let's look at the record on threats to boycott non-DRM broadcasting from these companies. In 2003, the US Broadcast Protection Discussion Group (a committee in the Hollywood-based Copy Protection Technical Working Group) went to work on a plan for adding DRM called the Broadcast Flag to America's high-def broadcasts. I attended every one of these meetings, working on behalf of the Electronic Frontier Foundation and the free/open TV projects it represented, including MythTV (an open video-recorder) and GNU Radio (an open radio/TV receiver).

Over and over again, the rightsholders in the room during the Broadcast Flag negotiations attempted to create a sense of urgency by threatening to boycott American high-def telly if they didn't get DRM. They repeated these threats in their submissions to the Federal Communications Commission (Ofcom's US counterpart) and in their meetings with American lawmakers.

They were very compelling. How compelling? Well, one ranking senator, Fritz Hollings, sent the head of the FCC a memo urging him to adopt the Broadcast Flag before America's entire HD transition collapsed in the face of a boycott. Hollings (whom Hill insiders used to call "The Senator from Disney") was so convinced by the MPAA's arguments that he let them write the memo he sent to the FCC, as we discovered when we downloaded the Word file the FCC posted and found metadata in it indicating that it had been composed on a computer registered to an MPAA staffer.

The FCC caved, just like Ofcom. They ruled that America would have DRM on its high-definition devices. They ruled, in effect, that holding a copyright in a movie or TV show gave you the right to design all the devices capable of playing it. This is exactly the same power that Ofcom wants to hand to the BBC: the right to tell you what your telly and all the devices connected to it can and can't do, how it must be designed, which kinds of industry can and can't build it. Not copyright, but "deviceright" — an unprecedented expansion of the modest right to control copies of your work into the right to design all devices capable of making copies.

So we sued. Along with the American Library Association and Public Knowledge, we asked a Federal judge to rule that the FCC didn't have the right to appoint itself Device Czar for America, with the power to approve or veto the features that one might build into a TV, a receiver, or a PC that might connect to either.

The court agreed with us. They recognised that being a telcoms regulator doesn't give you the right to regulate receivers and the devices they connect to. The Broadcast Flag died before it could be enacted.

And oh, you should have heard the copyright cartel! How they rattled their sabers and promised a boycott of HD that would destroy America's chances for an analogue switchoff. For example, the MPAA's CTO, Fritz Attaway, said that "high-value content will migrate away" from telly without DRM.

Viacom added: "[i]f a broadcast flag is not implemented and enforced by Summer 2003, Viacom's CBS Television Network will not provide any programming in high definition for the 2003-2004 television season."

One by one, the big entertainment companies – and sporting giants like the baseball and American football leagues – promised that without the Broadcast Flag, they would take their balls and go home.

So what happened? Did they make good on their threats? Did they go to their shareholders and explain that the reason they weren't broadcasting anything this year is because the government wouldn't let them control TVs?

No. They broadcast. They continue to broadcast today, with no DRM.

They were full of it. They did not make good on their threats. They didn't boycott.

They caved.

Which is exactly what they'll do today if Ofcom and the BBC stand up for the licence-paying public. After all, every American programme aired on British telly is aired first (or simultaneously) in the US, without DRM (because the Broadcast Flag was defeated). Which means that Britons who want to pirate HD TV can simply get a copy that originated on the American airwaves and not the British airwaves. Same programme, though.

What if the studios grow a spine this time around and make good on the threat? Well, so what? The BBC commissions telly. It can commission telly from British firms that are not so piracy-crazed that they demand DRM that doesn't work and pisses off the viewers. It'll be good for the balance of trade, too.

I love the Beeb, honestly I do. I am just as worried about charter renewal in 2016 as anyone in White City. But how on Earth can the BBC's masters believe that adding DRM will win over the affection of the Britons whose support Auntie will need during the next government?

Honestly, if you wanted to sabotage the BBC's future and abandon all hope of the licence fee, you could find no better starting point than this ridiculous exercise.

As for Ofcom, it's always disappointing when the entity appointed to be the grown-up in the relationship turns out to be just as credulous as its ward. Look, the Americans aren't going to boycott British telly, especially not in a down economy where their shareholders are baying for every penny. This is the same empty, ridiculous posturing they tried in 2003 in America, and the only thing dumber than their threats is your taking them seriously.

• Cory Doctorow is a digital activist, science fiction author and co-editor of the popular blog Boing Boing